CHECK, PLEASE! Bobby Bonilla, who last played for the Mets in 1999, will be collecting millions from the team for the next 25 years, supporting his lifestyle in a Greenwich, Conn., mansion. Photo: W.A. Funches Jr

(J.C. Rice)

Bobby Bonilla is about to add insult to injury.

The beleaguered Mets — hammered by Bernie Madoff’s fraud, free-agent flops and ballpark tumbleweeds — will soon start forking over $1.2 million annually for 25 years to the paunchy, 48-year-old ex-slugger who hasn’t picked up a bat in a decade.

Bonilla, a notorious malcontent who bombed on and off the field for the not-so-Amazin’s in the 1990s, will start collecting his nearly $30 million windfall on July 1. Thanks to a deferred deal he inked with the clueless club in 2000, he’ll collect seven-figure checks through 2035.

Not that Bobby Bo is short on dough. He pocketed some $50 million during his career, which included two stints in New York, and resides in an $8 million mansion in Greenwich, Conn.

Bonilla bought a couple of racehorses along the way and a fleet of luxury cars, including a Bentley and an antique Porsche. For open-air touring, there were four or five cus tom-made Harley-Davidson motorcycles, according to his ex-wife, Migdalia Bonilla.

The Bronx-born ballplayer has a pilot’s license, so he grabs the controls of his own Cessna or uses a time-share jet for his frequent jaunts to his family’s ancestral Puerto Rico or to Bradenton, Fla., where his 17-year-old son is a promising prep-school pitcher.

He sank about $2 million into fixing up the family’s stately white manse, tricking out the crib with high-tech gadgets.

“He wanted to redo it to be a ‘smart house,’ with a lot of technology,” said his ex, a high-school sweetheart Bonilla divorced in 2009 after 23 years of marriage.

For walking-around money, he holds a cushy $200,000-a-

year job as a “special assistant” at the MLB Players Association in Manhattan but doesn’t have to go into the office.

Asked what his duties entailed, a woman there said, “He just talks to the players.”

He also remains on the Baltimore Orioles’ payroll. That team’s $500,000-per-annum deferred payments began two months ago and extend until 2015. But he has to split that loot with the ex-wife.

Life will get even sweeter this summer thanks to the Mets, who are struggling to make payroll and hope to sell $200 million worth of the franchise to stay afloat.

Back in 1999, all they wanted was to get rid of Bonilla, who in between strikeouts fought with manager Bobby Valentine and who infamously played cards with fellow grumbler Rickey Henderson in the clubhouse while their teammates were losing the pennant in Atlanta.

But the Amazin’s still owed him $5.9 million for the next and final year of his bloated contract, so the two sides struck a deal: The Mets would put off paying until 2011 but would tack on 8 percent compounded interest, jacking the total tab to $29.8 million by the time it’s paid off.

Migdalia said she urged Robert, as she calls him, to accept the delayed deal.

“I made it very clear we can’t take [the lump-sum $5.9 million],” she said. “I said, ‘You’ll just end up spending it.’ “